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Circuit/System Testing

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  1. Ignition OFF and all vehicle systems OFF. Disconnect the harness connector at the B115 Vehicle Speed Sensor. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10 Ω between the low reference circuit terminal C and ground.
    • If 10 Ω or greater 
    1. Disconnect the X1 harness connector at the K20 Engine Control Module.
    2. Test for less than 2 Ω in the circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • Go to next step: If less than 10 Ω 
  3. Ignition ON.
  4. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal A and ground.
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the 5 V reference circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the 5 V reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • If greater than 5.2 V 
    1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module, Ignition ON.
    2. Test for less than 1 V between the 5 V reference circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K20 Engine Control Module.
    • Go to next step: If between 4.8 - 5.2 V 
  5. Ignition OFF, connect the test leads of the J-38522-A vehicle signal generator as follows:
    • Red test lead to the signal circuit terminal B at the B115 Vehicle Speed Sensor wire harness connector.
    • Black test lead to ground at the transmission case.
    • Double black power and ground lead wire to B+ and ground.
  6. Set and adjust the J-38522-A vehicle signal generator to the following switch positions:
    • Signal switch to 5 V.
    • Frequency switch to 600 Hz.
    • Duty cycle switch to 50% or normal position.
  7. Ignition ON.
  8. Verify the scan tool Vehicle Speed Sensor parameter displays between 40 - 52 km/h (25 - 32 mph).
    • If the vehicle speed sensor parameter is not within the specified range 
    1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the signal circuit terminal B and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • Go to next step: If the vehicle speed sensor parameter is within the specified range 
  9. Replace the B115 Vehicle Speed Sensor.
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